Various types of communication devices are available for communicating, managing, and handling data in a communication system such as a network. These communication devices include data terminal equipment (DTE), hubs, repeaters, network management units, and other devices capable of being coupled to another communication device or coupled to a network. Communication devices typically include one or more ports for transmitting and receiving data. These ports may be coupled to ports on other communication devices or coupled to a network.
In a network environment, multiple communication devices can be coupled together to permit the communication of data throughout the network. For example, a particular network may include several network hubs coupled to one another. In this example, each hub is capable of communicating with other hubs as well as communicating with and controlling communication devices coupled to the hub.
In known communication devices, a particular port may be designated as either a master port or a slave port (also referred to as a managed port or a controlled port). Network hubs typically have multiple ports for coupling to multiple communication devices. certain situations, a network hub may be used as a control device for multiple communication devices. At the same time, the hub may receive control signals from another network device, such as a master device. To provide for this situation, known network hubs include multiple ports, one or more of which are dedicated to coupling a control device. Other ports in the network hub are dedicated to coupling communication devices that are controlled by the hub. Since all ports in the network hub have a dedicated configuration, a hub that is used only to control other communication devices cannot utilize the ports dedicated to coupling to a control device. Therefore, the hub resources are not fully utilized because the controlled port cannot be used to couple network devices.
Additionally, known systems use separate communication links for transmitting data and transmitting management or control signals. Thus, a first port is provided for communicating data with another communication device, and a second port is provided for communicating management or control information with the other communication device. This configuration requires two separate communication links and a pair of ports on each communication device. The additional communication links and ports increase the overall cost and complexity of the communication devices and require additional physical space on the device to attach the additional ports.
It is therefore desirable to provide a communication system that is capable of transmitting both data and management information across a single communication link using a single communication port on each communication device.